2007-09-24 - 2007-10-01 - blog

mashoo

2007-09-24 - 2007-10-01

contents

2

000054df | 2007-09-24T10:47:17Z | radio > rx > antenna | -mt4-

75mm

000054de | 2007-09-24T10:47:19Z | radio > rx > antenna > width | -mt4-

ant main magloop, on door, az 260; fried my brain a bit, testing it with coupling loop as big as main loop up to 30w on 20, 15 and 10m

000054e0 | 2007-09-24T10:47:21Z | magnetic loop antenna, radio > comment | -mt4-

27.780 (27.779759)

000054e1 | 2007-09-24T10:47:23Z | radio > rx > frequency (mhz) | -mt4-

fm

000054e2 | 2007-09-24T10:47:25Z | radio > rx > mode | -mt4-

just missed some horseplay

000054e4 | 2007-09-24T10:47:29Z | radio > comment | -mt4-

more testing now, with start of coupling loop right up next to the start of the main loop

000054e5 | 2007-09-24T10:47:31Z | magnetic loop antenna, radio > comment | -mt4-

extended (> 3m) coupling loop produces better swr on 30m; therefore, reduce main loop width; actually, i'll try something else first; i seem to remember the swr on 20m being okay; perhaps lower the coupling loop again

000054e6 | 2007-09-24T11:17:43Z | magnetic loop antenna, radio > comment | -mt4-

27.780 (27.779759)

000054e7 | 2007-09-24T11:30:00Z | radio > rx > frequency (mhz) | -mt4-

on

000054e8 | 2007-09-24T11:30:02Z | radio > rx > pre-amp | -mt4-

14.145 (14.144877)

000054e9 | 2007-09-24T11:35:00Z | radio > rx > frequency (mhz) | -mt4-

usb

000054ea | 2007-09-24T11:35:02Z | radio > rx > mode | -mt4-

off

000054eb | 2007-09-24T11:35:04Z | radio > rx > pre-amp | -mt4-

where 3b7c is supposed to be; i don't hear him

000054ec | 2007-09-24T11:35:06Z | radio > comment | -mt4-

aluminium foil magnetic loop antenna on my bedroom door, complete with massive capacitor, sleeve choke balun and abxkoppel; the coupling loop has grown way too large

000045c5.jpg | 2007-09-24T11:57:54Z | magnetic loop antenna | -mt1-

bizarre close-up of a nasty implementation of abxkoppel

000045c7.jpg | 2007-09-24T11:59:42Z | magnetic loop antenna | -mt1-

massive capacitor hanging from the hook on my bedroom door

000045c9.jpg | 2007-09-24T12:00:46Z | magnetic loop antenna | -mt1-

coupling loop taped to the aluminium foil main loop

000045cb.jpg | 2007-09-24T12:01:36Z | magnetic loop antenna | -mt1-

21.295 (21.294815)

000054ed | 2007-09-24T12:15:20Z | radio > rx > frequency (mhz) | -mt4-

3b7c was here, they say; i don't hear him

000054ee | 2007-09-24T12:15:22Z | radio > comment | -mt4-

18.155 (18.154843)

000054ef | 2007-09-24T12:17:30Z | radio > rx > frequency (mhz) | -mt4-

[de yo3ais]

000086fa | 2007-09-24T12:17:32Z | radio > rx > message | -mt4-

rst 43

000054f1 | 2007-09-24T12:17:34Z | radio > comment | -mt4-

off

000054f3 | 2007-09-24T12:18:17Z | radio > on/off | -mt4-

anyway, about my magloop; i have photographed it in the condition in which an swr of 1:1 was achieved on 30m and 10m, using 30w (got fried again on 10m); 30m would object if the top of the coupling loop were too high; 10m would object if it were too low; perhaps the length of the capacitor was a factor in this discrepancy, a longer one being used for the 20 and 30m bands; since i did not want to do too much taping/untaping, i did not attempt any other adjustments of the coupling loop; however, i did end up remembering the twisting of the coupling loop ends, from online descriptions of abxkoppel; this had the effect of the swr 1:1 condition being maintained when i removed my hand from the capacitor knob; when i had first tried the twisting, 30m had objected, because the top of the coupling loop was too high or the coupling loop was too small or both; anyway, it's nice not to have sacrificed the thickness of the main loop; i still wonder whether the aluminium material is also a factor in 3 metres of coupling loop wire being required; if i had some copper foil, i might be able to prove this

000054f4 | 2007-09-24T12:18:19Z | magnetic loop antenna, radio > comment | -mt4-

1

000054f5 | 2007-09-24T14:48:25Z | radio > rx > antenna | -mt4-

14.145 (14.144877)

000054f6 | 2007-09-24T14:48:27Z | radio > rx > frequency (mhz) | -mt4-

[de 3b7c]

000086fb | 2007-09-24T14:48:29Z | radio > rx > message | -mt4-

14.152 (14.151877)

000054f9 | 2007-09-24T14:48:33Z | radio > tx > frequency (mhz) | -mt4-

14.168 (14.167877)

000054fa | 2007-09-24T15:04:00Z | radio > tx > frequency (mhz) | -mt4-

14.152 (14.151877)

000054fb | 2007-09-24T15:04:50Z | radio > tx > frequency (mhz) | -mt4-

2 cqs unanswered, during which i called

000054fc | 2007-09-24T15:11:10Z | radio > comment | -mt4-

clearest yet

000054fd | 2007-09-24T15:24:45Z | radio > comment | -mt4-

14.155 (14.154877)

000054fe | 2007-09-24T15:24:47Z | radio > tx > frequency (mhz) | -mt4-

14.152 (14.151877)

000054ff | 2007-09-24T15:37:40Z | radio > tx > frequency (mhz) | -mt4-

14.150 (14.149877)

00005500 | 2007-09-24T15:51:15Z | radio > tx > frequency (mhz) | -mt4-

change of operator; qsy 14.022 (?) cw

00005501 | 2007-09-24T15:59:20Z | radio > rx > message | -mt4-

frequency (mhz)

00005508 | 2007-09-24T16:02:08Z | radio > tx > frequency (mhz) | -mt4-

14.022 (14.021878)

00005502 | 2007-09-24T16:02:10Z | radio > rx > frequency (mhz) | -mt4-

cw

00005503 | 2007-09-24T16:02:12Z | radio > rx > mode | -mt4-

off

00005505 | 2007-09-24T16:05:51Z | radio > on/off | -mt4-

10.142 (10.141912)

00005507 | 2007-09-25T07:54:02Z | radio > rx > frequency (mhz) | -mt4-

2

00005509 | 2007-09-25T07:55:30Z | radio > rx > antenna | -mt4-

345

0000550a | 2007-09-25T07:55:32Z | radio > rx > antenna > azimuth (deg) | -mt4-

testing magloop with old linear capacitor; just measured the capacitor i used yesterday, as tuned for 30m; only ~ 105 pf, whereas my capacitor offers 176 pf

0000550b | 2007-09-25T07:55:34Z | magnetic loop antenna, radio > comment | -mt4-

10.117 (10.116912)

0000550c | 2007-09-25T07:55:36Z | radio > rx > frequency (mhz) | -mt4-

cq de df3rq

0000550f | 2007-09-25T07:55:40Z | radio > rx > message | -mt4-

28.005 (28.004757)

00005511 | 2007-09-25T07:56:52Z | radio > rx > frequency (mhz) | -mt4-

i need less capacitance than the minimum available here, so that i can tune above this frequency; i'll build a new linear capacitor, i suppose

00005512 | 2007-09-25T07:56:54Z | magnetic loop antenna, radio > comment | -mt4-

14.023 (14.022878)

00005513 | 2007-09-25T08:13:32Z | radio > rx > frequency (mhz) | -mt4-

14.020 (14.019878)

00005515 | 2007-09-25T08:14:40Z | radio > rx > frequency (mhz) | -mt4-

255

00005516 | 2007-09-25T08:14:42Z | radio > rx > antenna > azimuth (deg) | -mt4-

nice noise reduction

00005517 | 2007-09-25T08:14:44Z | radio > comment | -mt4-

14.023 (14.022878)

00005518 | 2007-09-25T08:18:00Z | radio > rx > frequency (mhz) | -mt4-

[de yt1e]

000086fc | 2007-09-25T08:18:02Z | radio > rx > message | -mt4-

1

0000551b | 2007-09-25T08:19:40Z | radio > rx > antenna | -mt4-

[de yt1e]

000086fd | 2007-09-25T08:19:40Z | radio > rx > message | -mt4-

no matching network

0000551c | 2007-09-25T08:19:42Z | radio > comment | -mt4-

2

0000551d | 2007-09-25T08:21:25Z | radio > rx > antenna | -mt4-

14.052 (14.051878)

0000551e | 2007-09-25T08:22:15Z | radio > rx > frequency (mhz) | -mt4-

quick flick between antennas

0000551f | 2007-09-25T08:23:00Z | radio > comment | -mt4-

14.040 (14.039878)

00005520 | 2007-09-25T08:25:00Z | radio > rx > frequency (mhz) | -mt4-

14.052 (14.051878)

00005521 | 2007-09-25T08:28:15Z | radio > rx > frequency (mhz) | -mt4-

14.033 (14.032878)

00005522 | 2007-09-25T08:29:03Z | radio > rx > frequency (mhz) | -mt4-

quick flick; good demo of loop low noise

00005523 | 2007-09-25T08:29:05Z | magnetic loop antenna, radio > comment | -mt4-

off

00005524 | 2007-09-25T08:31:08Z | radio > on/off | -mt4-

breakfast

00005525 | 2007-09-25T08:31:10Z | radio > comment | -mt4-

breakfast delayed; i'm examining boosted magloop audio; wondering what a small signal would be like with the narrow cw filter

00005527 | 2007-09-25T08:39:33Z | magnetic loop antenna, radio > comment | -mt4-

14.03525 (14.035128)

00005528 | 2007-09-25T08:43:35Z | radio > rx > frequency (mhz) | -mt4-

here's some

00005529 | 2007-09-25T08:43:37Z | radio > comment | -mt4-

that'll do

0000552a | 2007-09-25T08:44:14Z | radio > comment | -mt4-

off

0000552b | 2007-09-25T08:44:16Z | radio > on/off | -mt4-

a magnetic loop antenna main conductor made from 15mm copper tube hastily bent into shape; i wanted to see whether it behaved differently to to aluminium foil i could not get to work the way i wanted

000045d2.jpg | 2007-09-25T17:55:52Z | magnetic loop antenna | -mt1-

i've been playing with the magloop again today; the most recent development is that i have cut the aluminium foil prototype from 3 metres to 2.8 metres, which is the perimeter of the magloop deployed previously; at nearly 30 mhz, the capacitance required is 13pf; magloop4 suggests that the maximum capacitance (for 10 mhz) would be ~ 190pf, with an efficiency at that lowest frequency of just over 50%, at 3m high over average ground; the minimum capacitance is the worry at the moment, since my preliminary fiddlings with the remains of my old linear capacitor have yielded minimum values of about 12pf; i would like more breathing space than 1 pf; smaller plates would cause less stray capacitance, and my current idea is to extend my linear capacitor design to multiple mobile plates; also, i wonder whether the so-called stators should be the mobile ones; anyway, it's been a long day; goodnight

0000552c | 2007-09-25T20:16:19Z | magnetic loop antenna | -mt4-

one more thing about yesterday's endeavours with the magloop; i spent a lot of time unfurling the main loop and trying a smaller coupling loop and such things, in an attempt to explain the discrepancy between magloop4's capacitance predictions and the values i was getting from my multimeter; as with the ~60cm perimeter loop i experimented with (before constructing my original magloop), i had forgotten about the long test leads connecting the main loop to the capacitor; with little or no test leads, results became normal; and one more `one more thing'; using magloop4 and my multimeter, i came to the conclusion that the equivalent diameter of my aluminium foil `flat tube' is about 70mm

0000552d | 2007-09-26T06:39:47Z | magnetic loop antenna | -mt4-

1

0000552e | 2007-09-26T08:01:47Z | radio > rx > antenna | -mt4-

3.705 (3.704968)

0000552f | 2007-09-26T08:01:49Z | radio > rx > frequency (mhz) | -mt4-

lsb

00005530 | 2007-09-26T08:01:51Z | radio > rx > mode | -mt4-

3.708 (3.707968)

00005532 | 2007-09-26T08:03:00Z | radio > rx > frequency (mhz) | -mt4-

tuned

00005533 | 2007-09-26T08:05:30Z | radio > comment | -mt4-

tuned with 30w

00005534 | 2007-09-26T08:12:52Z | radio > comment | -mt4-

[de g3kng]

000086fe | 2007-09-26T08:14:45Z | radio > rx > message | -mt4-

rst 59+10

00005536 | 2007-09-26T08:14:47Z | radio > comment | -mt4-

[de g3rva]

000086ff | 2007-09-26T08:19:30Z | radio > rx > message | -mt4-

rst 33

00005538 | 2007-09-26T08:19:32Z | radio > comment | -mt4-

[de g3rsx] name graham; qth castlecroft; rig ic-756; ant dipole

0000553b | 2007-09-26T08:23:01Z | radio > rx > message | -mt4-

rst 59+20

0000553a | 2007-09-26T08:23:02Z | radio > comment | -mt4-

[de g3jjr] qth compton; name john; rig ic-706; ant dipole

0000553e | 2007-09-26T08:27:26Z | radio > rx > message | -mt4-

rst 59+60

0000553d | 2007-09-26T08:27:27Z | radio > comment | -mt4-

[de g3kng]

00008700 | 2007-09-26T08:29:28Z | radio > rx > message | -mt4-

rst 59+10

00005540 | 2007-09-26T08:29:30Z | radio > comment | -mt4-

[g0vbc de g3kng] was in kingsbridge, devon, 2 weeks ago, so i heard you; super signal; bill was rst 58; i was bigger; today, rst 59+; full net list probably too big for a qso; conversations tend to repeat themselves

00005542 | 2007-09-26T08:29:33Z | radio > rx > message | -mt4-

[g0vbc de g3rva] rst 56

00005545 | 2007-09-26T08:34:13Z | radio > rx > message | -mt4-

rst 59

00005544 | 2007-09-26T08:34:14Z | radio > comment | -mt4-

[de g3rsx] interested in fstv into repeater in sedgley and stoke-on-trent

00005549 | 2007-09-26T08:39:11Z | radio > rx > message | -mt4-

rst 59+30

00005548 | 2007-09-26T08:39:14Z | radio > comment | -mt4-

[de g3kng]

00008702 | 2007-09-26T08:41:00Z | radio > rx > message | -mt4-

rst 59+10

0000554b | 2007-09-26T08:41:02Z | radio > comment | -mt4-

[de g3jjr] wolverhampton radio club used to meet near here

0000554d | 2007-09-26T08:43:41Z | radio > rx > message | -mt4-

this group started with a shock on a sunday with a yl, the wife of one of our crowd, calling in; and then john joined; and then the time changed to this; that's history

0000554f | 2007-09-26T08:51:22Z | radio > rx > message | -mt4-

[g0vbc de g3kng] your 30w and antenna doing well

00005552 | 2007-09-26T08:55:03Z | radio > rx > message | -mt4-

middle of cool story about top brand crap gear

00005553 | 2007-09-26T09:13:45Z | radio > comment | -mt4-

middle of another cool story about neighbour complaints

00005555 | 2007-09-26T09:17:00Z | radio > comment | -mt4-

[g0vbc de g3rsx]

00008704 | 2007-09-26T09:17:00Z | radio > rx > message | -mt4-

off

00005557 | 2007-09-26T09:18:32Z | radio > on/off | -mt4-

pretty trees and blue sky from my bedroom window

000045e5.jpg | 2007-09-27T08:14:34Z | -no-label- | -mt1-

pretty trees and blue sky from my bedroom window

000045e9.jpg | 2007-09-27T08:16:40Z | -no-label- | -mt1-

sunny fence and odd little table from my bedroom window

000045eb.jpg | 2007-09-27T08:18:04Z | -no-label- | -mt1-

waitrose air and water station

000045ed.jpg | 2007-09-27T10:48:06Z | -no-label- | -mt1-

motor-driven linear capacitor reading 14 picofarads at minimum

000045fa.jpg | 2007-09-28T08:02:02Z | magnetic loop antenna | -mt1-

5.3715 (5.371453)

00005558 | 2007-09-29T17:07:52Z | radio > rx > frequency (mhz) | -mt4-

usb

00005559 | 2007-09-29T17:07:54Z | radio > rx > mode | -mt4-

[de ?]

00008705 | 2007-09-29T17:07:58Z | radio > rx > message | -mt4-

7.097 (7.096938)

0000555e | 2007-09-29T17:08:47Z | radio > rx > frequency (mhz) | -mt4-

lsb

0000555f | 2007-09-29T17:08:49Z | radio > rx > mode | -mt4-

[de ei75irts]

00008706 | 2007-09-29T17:08:51Z | radio > rx > message | -mt4-

rst 59+20

00005561 | 2007-09-29T17:08:53Z | radio > comment | -mt4-

5.3715 (5.371453)

00005563 | 2007-09-29T17:10:40Z | radio > rx > frequency (mhz) | -mt4-

usb

00005564 | 2007-09-29T17:10:42Z | radio > rx > mode | -mt4-

off

00005565 | 2007-09-29T17:11:25Z | radio > on/off | -mt4-

5.343 (5.342954)

00005566 | 2007-09-30T09:27:01Z | radio > rx > frequency (mhz) | -mt4-

away

00005568 | 2007-09-30T09:36:47Z | radio > comment | -mt4-

5.505 (5.504952)

00005569 | 2007-09-30T10:40:45Z | radio > rx > frequency (mhz) | -mt4-

[de ?]

00008707 | 2007-09-30T10:40:47Z | radio > rx > message | -mt4-

rst 59+10

0000556b | 2007-09-30T10:40:49Z | radio > comment | -mt4-

5.343 (5.342954)

0000556d | 2007-09-30T10:41:02Z | radio > rx > frequency (mhz) | -mt4-

5.3985 (5.398453)

0000556e | 2007-09-30T10:47:45Z | radio > rx > frequency (mhz) | -mt4-

[de gw0vmz]

00008708 | 2007-09-30T10:47:47Z | radio > rx > message | -mt4-

rst 22

00005570 | 2007-09-30T10:47:49Z | radio > comment | -mt4-

5.343 (5.342954)

00005571 | 2007-09-30T10:48:10Z | radio > rx > frequency (mhz) | -mt4-

off

00005572 | 2007-09-30T10:53:45Z | radio > on/off | -mt4-

it strikes me that audacity's 20% of the processor is a bit excessive

00005573 | 2007-09-30T10:53:47Z | radio > comment | -mt4-

5.3985 (5.398453)

00005574 | 2007-09-30T11:07:45Z | radio > rx > frequency (mhz) | -mt4-

[de ?]

00008709 | 2007-09-30T11:07:47Z | radio > rx > message | -mt4-

welsh

00005576 | 2007-09-30T11:07:49Z | radio > comment | -mt4-

off

00005578 | 2007-09-30T11:11:42Z | radio > on/off | -mt4-

5.4035 (5.403453)

00005579 | 2007-09-30T12:52:51Z | radio > rx > frequency (mhz) | -mt4-

[de g4rqj/p] qth np-031

0000557c | 2007-09-30T12:52:56Z | radio > rx > message | -mt4-

rst 57

0000557d | 2007-09-30T12:52:59Z | radio > comment | -mt4-

[g0vbc de g4rqj/p] name rob; rst 58; wx sunny; nice views all around

0000557f | 2007-09-30T12:54:47Z | radio > rx > message | -mt4-

[g0vbc de g4rqj/p]

0000870a | 2007-09-30T12:56:28Z | radio > rx > message | -mt4-

off

00005581 | 2007-09-30T12:58:10Z | radio > on/off | -mt4-

cq mm0tss

00005583 | 2007-09-30T18:07:18Z | radio > tx > message | -mt4-

(msn) nothing heard

00005584 | 2007-09-30T18:07:20Z | radio > comment | -mt4-

[de mm0tss]

0000870b | 2007-09-30T18:12:10Z | radio > rx > message | -mt4-

rst 11

00005587 | 2007-09-30T18:12:14Z | radio > comment | -mt4-

toby qrt for roast duck

00005588 | 2007-09-30T18:17:00Z | radio > comment | -mt4-

off

00005589 | 2007-09-30T18:17:02Z | radio > on/off | -mt4-

1.912 (1.911983)

0000558a | 2007-09-30T21:00:48Z | radio > rx > frequency (mhz) | -mt4-

lsb

0000558b | 2007-09-30T21:00:50Z | radio > rx > mode | -mt4-

unknown, sounds local

0000558e | 2007-09-30T21:05:32Z | radio > comment | -mt4-

rst 59+20

0000558f | 2007-09-30T21:05:34Z | radio > comment | -mt4-

[de gw0dck/p]

0000870c | 2007-09-30T21:07:52Z | radio > rx > message | -mt4-

rst 59

00005591 | 2007-09-30T21:07:54Z | radio > comment | -mt4-

[de ?] switched to vertical

00005593 | 2007-09-30T21:12:11Z | radio > rx > message | -mt4-

rst 59+30

00005594 | 2007-09-30T21:12:14Z | radio > comment | -mt4-

switched back again

00005595 | 2007-09-30T21:12:16Z | radio > rx > message | -mt4-

[de g0rrm]

0000870d | 2007-09-30T22:06:25Z | radio > rx > message | -mt4-

rst 59

00005597 | 2007-09-30T22:06:27Z | radio > comment | -mt4-

off

00005599 | 2007-09-30T22:19:12Z | radio > on/off | -mt4-

contents

matthew munro, g0vbc, my bedroom, wolverhampton, still photograph